diff --git a/backend/app/api/users.py b/backend/app/api/users.py
index 57f594d..991e685 100644
--- a/backend/app/api/users.py
+++ b/backend/app/api/users.py
@@ -95,6 +95,12 @@ async def change_user_status(
             status_code=403, detail="Cannot manage users outside your class"
         )
 
+    # Only super_admin can change roles
+    if data.role and admin.role != "super_admin":
+        raise HTTPException(
+            status_code=403, detail="Only super admin can change user roles"
+        )
+
     updated = await update_user_status(db, user_id, data.status, data.role)
 
     # Send email notification
diff --git a/frontend/src/app/(app)/admin/members/page.tsx b/frontend/src/app/(app)/admin/members/page.tsx
index 43baa29..92ffc6b 100644
--- a/frontend/src/app/(app)/admin/members/page.tsx
+++ b/frontend/src/app/(app)/admin/members/page.tsx
@@ -481,23 +481,27 @@ export default function MembersPage() {
                           </p>
                         </div>
                         <div className="flex items-center gap-2">
-                          <Select
-                            value={m.role}
-                            onValueChange={(v) => v && handleRoleChange(m.id, v)}
-                          >
-                            <SelectTrigger className="w-28 h-7 text-xs">
-                              <SelectValue>
-                                {ROLES[m.role as keyof typeof ROLES] || m.role}
-                              </SelectValue>
-                            </SelectTrigger>
-                            <SelectContent>
-                              <SelectItem value="student">同学</SelectItem>
-                              <SelectItem value="class_admin">班级管理员</SelectItem>
-                              {isSuperAdmin && (
+                          {isSuperAdmin ? (
+                            <Select
+                              value={m.role}
+                              onValueChange={(v) => v && handleRoleChange(m.id, v)}
+                            >
+                              <SelectTrigger className="w-28 h-7 text-xs">
+                                <SelectValue>
+                                  {ROLES[m.role as keyof typeof ROLES] || m.role}
+                                </SelectValue>
+                              </SelectTrigger>
+                              <SelectContent>
+                                <SelectItem value="student">同学</SelectItem>
+                                <SelectItem value="class_admin">班级管理员</SelectItem>
                                 <SelectItem value="super_admin">超级管理员</SelectItem>
-                              )}
-                            </SelectContent>
-                          </Select>
+                              </SelectContent>
+                            </Select>
+                          ) : (
+                            <Badge variant="outline">
+                              {ROLES[m.role as keyof typeof ROLES] || m.role}
+                            </Badge>
+                          )}
                           {getStatusBadge(m.status)}
                           {m.status === "approved" && (
                             <Button
diff --git a/frontend/src/components/sidebar.tsx b/frontend/src/components/sidebar.tsx
index 6b197f3..a796823 100644
--- a/frontend/src/components/sidebar.tsx
+++ b/frontend/src/components/sidebar.tsx
@@ -3,8 +3,9 @@
 import Link from "next/link";
 import { usePathname } from "next/navigation";
 import { useSidebar } from "@/hooks/use-sidebar";
-import { RoleGuard } from "@/components/role-guard";
 import { cn } from "@/lib/utils";
+import type { UserRole } from "@/lib/types";
+import { useAuth } from "@/hooks/use-auth";
 
 const navItems = [
   { href: "/dashboard", label: "首页", icon: "M3 12l2-2m0 0l7-7 7 7M5 10v10a1 1 0 001 1h3m10-11l2 2m-2-2v10a1 1 0 01-1 1h-3m-6 0a1 1 0 001-1v-4a1 1 0 011-1h2a1 1 0 011 1v4a1 1 0 001 1m-6 0h6" },
@@ -19,13 +20,17 @@ const navItems = [
 ];
 
 const adminItems = [
-  { href: "/admin/members", label: "成员管理", icon: "M12 4.354a4 4 0 110 5.292M15 21H3v-1a6 6 0 0112 0v1zm0 0h6v-1a6 6 0 00-9-5.197M13 7a4 4 0 11-8 0 4 4 0 018 0z" },
-  { href: "/admin/classes", label: "班级管理", icon: "M19 21V5a2 2 0 00-2-2H7a2 2 0 00-2 2v16m14 0h2m-2 0h-5m-9 0H3m2 0h5M9 7h1m-1 4h1m4-4h1m-1 4h1m-5 10v-5a1 1 0 011-1h2a1 1 0 011 1v5m-4 0h4" },
+  { href: "/admin/members", label: "成员管理", icon: "M12 4.354a4 4 0 110 5.292M15 21H3v-1a6 6 0 0112 0v1zm0 0h6v-1a6 6 0 00-9-5.197M13 7a4 4 0 11-8 0 4 4 0 018 0z", roles: ["super_admin", "class_admin"] as UserRole[] },
+  { href: "/admin/classes", label: "班级管理", icon: "M19 21V5a2 2 0 00-2-2H7a2 2 0 00-2 2v16m14 0h2m-2 0h-5m-9 0H3m2 0h5M9 7h1m-1 4h1m4-4h1m-1 4h1m-5 10v-5a1 1 0 011-1h2a1 1 0 011 1v5m-4 0h4", roles: ["super_admin"] as UserRole[] },
 ];
 
 export function Sidebar() {
   const pathname = usePathname();
   const { isOpen, close } = useSidebar();
+  const { user } = useAuth();
+  const visibleAdminItems = user
+    ? adminItems.filter((item) => item.roles.includes(user.role))
+    : [];
 
   return (
     <>
@@ -80,41 +85,43 @@ export function Sidebar() {
           </Link>
         ))}
 
-        <RoleGuard roles={["super_admin", "class_admin"]}>
-          <div className="pt-4 pb-2">
-            <p className="px-3 text-xs font-semibold text-gray-400 uppercase tracking-wider">
-              管理
-            </p>
-          </div>
-          {adminItems.map((item) => (
-            <Link
-              key={item.href}
-              href={item.href}
-              onClick={close}
-              className={cn(
-                "flex items-center gap-3 px-3 py-2 rounded-lg text-sm transition-colors",
-                pathname.startsWith(item.href)
-                  ? "bg-gray-900 text-white"
-                  : "text-gray-600 hover:bg-gray-100"
-              )}
-            >
-              <svg
-                className="w-5 h-5 shrink-0"
-                fill="none"
-                stroke="currentColor"
-                viewBox="0 0 24 24"
+        {visibleAdminItems.length > 0 && (
+          <>
+            <div className="pt-4 pb-2">
+              <p className="px-3 text-xs font-semibold text-gray-400 uppercase tracking-wider">
+                管理
+              </p>
+            </div>
+            {visibleAdminItems.map((item) => (
+              <Link
+                key={item.href}
+                href={item.href}
+                onClick={close}
+                className={cn(
+                  "flex items-center gap-3 px-3 py-2 rounded-lg text-sm transition-colors",
+                  pathname.startsWith(item.href)
+                    ? "bg-gray-900 text-white"
+                    : "text-gray-600 hover:bg-gray-100"
+                )}
               >
-                <path
-                  strokeLinecap="round"
-                  strokeLinejoin="round"
-                  strokeWidth={1.5}
-                  d={item.icon}
-                />
-              </svg>
-              {item.label}
-            </Link>
-          ))}
-        </RoleGuard>
+                <svg
+                  className="w-5 h-5 shrink-0"
+                  fill="none"
+                  stroke="currentColor"
+                  viewBox="0 0 24 24"
+                >
+                  <path
+                    strokeLinecap="round"
+                    strokeLinejoin="round"
+                    strokeWidth={1.5}
+                    d={item.icon}
+                  />
+                </svg>
+                {item.label}
+              </Link>
+            ))}
+          </>
+        )}
       </nav>
 
       <div className="p-4 border-t border-gray-200">